Throughout time human beings have been drawn to the great unknown, and nowhere offers so many unknowns, in a relatively accessible place, as the ocean. There, lovers of the strange and bewildering can find stories of ghost ships, immortal jellyfish, unidentifiable sounds, and alien-looking objects.
Milky Sea Phenomenon
The Milky Sea phenomenon is one of the best-known ocean oddities. It refers to a strange milky sheen/glow found on the waters of the Indian Ocean. This phenomenon has been detailed for more than 400 years by sailors and scientists. In 2006, researches determined that the glow came from bioluminescent bacteria. This odd skill allows them to attract fish, be consumed, and then thrive on the bacteria in the fish’s stomach. While this part of the mystery has been solved, it’s still unclear why such massive numbers of bacteria gather together in the same location.
The Kaz II
The Kaz II was a yacht that was found adrift 163 kilometers off the coast of Australia in 2007. The three crew members were nowhere to be found, and their fates have never been determined. The ship was crewed by Derek Batten, Peter Tunstead, and James Tunstead. It separated from Airlie Beach five days before it was discovered adrift. They were headed fo Townsville, Queensland, and then around to Western Australia. When investigated, the ship was completely intact with everything exactly as one would expect it to be.
Food, plates, and silverware were ill on the tables, a laptop was on and working, and the engine was running. The GPS was fully functional, as was the radio. The only sign of distress, besides the missing crew, was one of the sails had been shredded, and there was no life raft on board. There is still no clear conclusion regarding the fate of the crew.
Bermeja

Bermeja is a mysterious phantom island off the coast of the Yucatan peninsula. It is noted on several maps from the 16th to 20th centuries, but no modern survey has ever uncovered it. It was first mentioned in a list of islands published in Madrid in 1539. Some believe that the island never existed while others have suggested that it disappeared somehow. Perhaps rising sea levels consumed it, or as another more outlandish theory suggests, maybe the CIA destroyed the island to expand the US economic zone.
Baltic Sea Anomaly
The Baltic Sea anomaly refers to a sonar image taken by several scientists, including Peter Lindeberg and Dennis Åberg. They, along with their diving team, “Ocean X,” took the image while treasure hunting along the floor of the northern Baltic Sea in June 2011. The object in the picture was strikingly unusual, seemingly non-natural. Some people immediately jumped to the conclusion that it was an underwater UFO, while more even-minded scientists determined that it was a geological formation.
The image shows something that is 200 ft, or 60m in diameter. It appears circle with features than some see as resembling ramps and stairs. When the group tried to take another photo the next year, they claimed that some electrical interference prevents them from doing so. Other suggestions were that the formation was a portal to another dimension or some kind of underwater monument like Stonehenge. Live Science describes the formation as a glacial deposit although this answer has not satisfied the most avid of conspiracy theorists.
Mysterious Sounds
One of the most famous “mysterious sounds” is the “bloop,” recorded in the 1990s. It originated from the southern Pacific and was recorded while scientists were listening for underwater volcanic activity. Some possible origins for the sound, from the scientific community, were secret military exercises, giants squids, whales, commercial fishing boats, or possibly a sea creature as of yet unknown to science.
It was eventually determined that the sound was an icequake or the sound of an iceberg cracking and breaking away from a glacier. While the origin of this particular sound was uncovered, many more such as low, screeching sounds originating from the Mariana Trench are not fully explained.
The Green Flash

The green flash is a meteorological phenomenon that can occur around the moment of sunrise or sunset. It requires perfect conditions and resembles a green-ray that shoots up from the sunrise/sunset point. They have fueled stories and myths for decades, but scientists now understand them as the effect of the earth’s atmosphere causing the Sun’s light to refract into different colors.
Immortal Jellyfish
As hard as it might seem to believe, there is a creature on earth that can live forever. Turritopsis dohrnii, or the immortal jellyfish, is relatively small, only 4.5mm or 0.18 inches. It has up to 90 tentacles and a transparent stomach featuring one patch of red. When damaged, the jellyfish has the remarkable ability to jump back in its developmental history and repair the damage that was done. It returns to an early stage, that of a polyp, and eventually reforms into the same, genetically identity adult. This is a process known as transdifferentiation and is, quite obviously, of great medical interest to scientists.
Some believe that if the mysterious in the jellyfish’s stem cells could be unlocked, it might hold the key to human immortality.
Mariana Trench

The Mariana Trench is well-known as the deepest part of the ocean. It is located in the western pacific and it reaches a depth of 10,994 meters, or possibly deeper, up to 11,000+ meters, or around 36,000ft. No one has ever been to the very bottom of the Marina Trench, making it one of the most interesting unexplored parts of the oceans. The deepest part of the trench is known as the “Challenger Deep.” It is named for the HMS Challenger and the Challenger II. The waters in the trench vary between being frigid to scaldingly hot at 700 degrees Fahrenheit
1968 Submarine Disappearances
In 1968, at least four submarines from different countries disappeared into the oceans. One of the most famous is the USS Scorpion, which fact off the coast of the Azores in the Atlantic Ocean. There are several theories about what happened to it and what happened to the other three subs—the INS Darak from Israel, the Minerve from France, and the K-129 from the Soviet Union. Theories abound in regards to what occurred to all four of these subs. Some believe it was an unlucky coincidence, while others are willing to entertain notions of sea monsters and various unnatural phenomena.
The Bermuda Triangle Ocean Mysteries

No list of ocean mysteries would be complete with mentioning the Bermuda Triangle. It is also known as the Devil’s triangle. It is defined as a region of the ocean, off Florida and Puerto Rico in the Atlantic, where an unusual number of ships and planes have disappeared. The mystery first started gaining traction in the 1950s with the disappearance of Flight 19. Popular media has depicted the area as a haven for supernatural activity, spinning compasses, and even alien abduction. But, in truth, it is one of the most heavily traveled areas of the ocean, and the number of disappearances is not disproportional for the traffic in the area.